A method of cutting glass

Abstract

The application discloses a glass cutting method, provides a laser device, the laser device has signal light of first wavelength and pump light of second wavelength, the pump light is absorbed and converted into signal light in an amplifier, and the method is characterized in that: the outgoing laser beam is composed of signal light and unabsorbed residual pump light, the energy of the residual pump light is greater than 15% of the total energy of the pump light, the outgoing laser beam is divided into two beams by a wavelength spectrometer, the separated residual pump light is adjusted in size by a beam expanding system and then recombined, and is focused on the glass to be processed; micro-cracks are formed in the glass by the outgoing signal light beam; the micro-cracks in the glass are controlled to expand by the modulated residual pump light beam; the focused laser spot is scanned along a cutting path on the glass to be processed; and the glass is cut. The application only needs one laser light source to complete the cutting of the glass in one process.

Description

TECHNICAL FIELD

[0001] The present application relates to a laser processing method, in particular to a method for processing glass by laser. BACKGROUND

[0002] In the fields of consumer electronics, semiconductors, new energy, precision optics, aerospace, etc., glass materials are widely used due to their high light transmittance, good strength, wear resistance, and special photoelectric functional characteristics. With higher requirements for the efficiency, precision, and yield of glass processing in high-end applications, laser processing gradually replaces traditional glass mechanical processing methods.

[0003] As for the laser glass cutting process, common methods include hidden cutting and filament cutting. These methods usually involve two process steps, i.e., first forming microcracks on the material using laser (laser cutting step), and then allowing the microcracks to expand controllably to separate the glass material to be cut (cracking step). The cracking step can be mechanical cracking or using another CO2 laser to heat the cracks.

[0004] For example, Chinese invention application CN114985990A discloses a double-laser cracking method. It uses two laser sources as energy sources, including an ultrashort pulse laser and a short pulse or continuous laser. The ultrashort pulse laser beam is first focused inside the material, and due to nonlinear absorption, a crack is formed inside the material. After the ultrashort pulse laser beam, a short pulse or continuous laser is used to irradiate the inside of the material, and due to thermal characteristics, the crack propagates, achieving the effect of cutting and cracking.

[0005] In this type of processing method, since there are two processing procedures of cutting and cracking, two laser sources are required, or mechanical cracking or thermal cracking methods are used for the cracking procedure, which results in more process steps, relatively complex equipment structure, reduced system automation, and longer process flow. SUMMARY

[0006] The purpose of the present application is to provide a glass cutting method that uses one laser source to complete laser cutting and cracking operations in one process, reducing system complexity and improving laser cutting efficiency.

[0007] To achieve the above-mentioned purpose of the invention, the technical solution adopted by the present invention is: a glass cutting method, providing a laser device, the laser device having a signal light of a first wavelength and a pump light of a second wavelength, the pump light is absorbed in an amplifier and converted into signal light, the outgoing laser beam is composed of the signal light and the unabsorbed residual pump light, the energy of the residual pump light is greater than 15% of the total energy of the pump light, a wavelength splitter is used to split the outgoing laser beam into two beams, namely the outgoing signal beam and the residual pump beam, the separated residual pump light is adjusted in size by a beam expansion system and then recombined with the outgoing signal beam and focused on the glass to be processed, the outgoing signal beam forms microcracks in the glass, the modulated residual pump beam causes the microcracks in the glass to expand in a controlled manner, and the focused laser spot scans the glass to be processed along the cutting path to achieve glass cutting.

[0008] In the above technical solution, the first wavelength is 1020nm~1080nm, and the second wavelength is 910nm~980nm.

[0009] In the above technical solution, the initial signal light is provided by a seed laser source, which is a nanosecond or picosecond pulse laser generator.

[0010] In a preferred technical solution, the seed laser source is a pulse directly generated by an electrically modulated semiconductor laser, or a femtosecond mode-locked laser pulse with a wide spectrum that is broadened to a pulse width of hundreds of picoseconds via a dispersion element.

[0011] In the above technical solution, the average output power of the seed laser source is less than 2 watts.

[0012] The present invention can use a 910-980 nanometer semiconductor laser as a pump source to pump a rare earth ytterbium ion-doped optical fiber to form an amplifier to amplify the power of the seed laser light source.

[0013] The amplifier can be a single-stage amplifier or a multi-stage amplifier structure consisting of multiple cascaded amplifiers. In these amplifiers, the 910-980 nm pump laser light cannot be fully absorbed and converted into 1020-1080 nm signal light. Depending on the design of the final amplifier, more than 15% of the energy will not be absorbed and will continue to be transmitted along with the signal light in the output fiber.

[0014] In the above technical solution, the output laser beam is focused on the glass to be processed through the galvanometer and the field lens, and the glass is cut and split.

[0015] Alternatively, the output laser beam is focused on the glass to be processed through a converging lens to cut and split the glass.

[0016] A technical solution, the glass to be processed is arranged on a worktable, and the worktable has the freedom of horizontal two-dimensional movement.

[0017] Due to the use of the above technical solution, the present application has the following advantages compared with the prior art:

[0018] 1. Due to the pumping absorption efficiency, the short-wavelength pumping light in the fiber laser cannot be fully absorbed, and this energy becomes waste heat in the prior art and is taken away by the cooling system. The present application creatively utilizes the residual pumping light to form micro-cracks in the glass by the main output laser, and uses the residual pumping light to control the expansion of the micro-cracks in the glass, so that only one laser light source is needed to complete the cutting of the glass in one process.

[0019] 2. The present application divides the outgoing laser beam into beams by wavelength, so that the residual pumping light can be independently changed in spot size by the beam expanding system without affecting the signal light, and is not restricted by the pumping power of the laser amplifier. By adjusting the spot size of the residual pumping light, better cracking effect can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of the cutting device of the embodiment of the present application;

[0021] Figure 2 is a schematic diagram of the beam splitting and expanding part in the embodiment. EMBODIMENT

[0022] The present application will be further described below in combination with the drawings and embodiments:

[0023] Embodiment one: a laser cutting method of glass, which is realized by using the device shown in Figure 1 . Referring to Figure 1 and Figure 2 , the device comprises a laser device composed of a laser seed source 1, a laser pre-amplifier 3, a laser main amplifier 5, a pumping semiconductor laser 2, 4, a beam splitting and combining device composed of dichroic mirrors 6, 9, a 45-degree mirror 7, 8, a 45-degree mirror 10 for changing the outgoing direction of the laser, a galvanometer 11, and a field lens 12 for controlling the focusing position of the laser, and the glass to be cut 13 is placed on the object platform 14.

[0024] In this embodiment, the laser seed source 1 outputs infrared laser with a wavelength of 1030 nm, a repetition frequency of 1 MHz, a pulse width of 10 ps, and a power of 50 mW. The semiconductor laser 2 outputs 976 nm laser, the laser pre-amplifier 3 (fiber amplifier) amplifies the laser output by the seed source 1 to 500 mW, the semiconductor laser 4 outputs 150 W of 976 nm laser, and the laser main amplifier 5 amplifies the 1030 nm picosecond laser to 60 W. The signal light transmits through the dichroic mirror 6 and continues to transmit in the optical path. The laser main amplifier 5 does not completely absorb all the laser output by the semiconductor laser 4, and the remaining 50 W of 976 nm laser is reflected by the dichroic mirror into the mirror 7 and continues to transmit in the optical path. The beam expander system 16 is arranged between the mirrors 7 and 8 to control the beam of the remaining 50 W of 976 nm laser to control the spot size. For example, a 4x beam expander can be arranged to expand the pump light, so that a spot with a smaller divergence angle can be obtained. The 50 W of 976 nm residual pump laser and the 60 W of 1030 nm picosecond laser output by the laser are combined at the dichroic mirror 9, enter the galvanometer 11 and the field lens 12 through the mirror 10, and finally enter the surface of the glass to be cut. On the surface of the glass to be cut 13, the 1030 nm picosecond laser acts to form microcracks, and under the thermal effect of the 976 nm continuous laser, the microcracks grow controllably, and the glass is cut.

[0025] The embodiment can reduce the glass cutting process. The system has low complexity and high cutting efficiency, can effectively reduce the equipment and personnel costs of the glass cutting process, and maintain good laser cutting effect of the glass.

Claims

1. A method of cutting glass, providing a laser device having a signal light of a first wavelength and a pump light of a second wavelength, the pump light being converted into the signal light in an amplifier, characterized in that: The outgoing laser beam is composed of signal light and unabsorbed residual pump light, the energy of the residual pump light is greater than 15% of the total energy of the pump light, the outgoing laser beam is divided into two beams by a wavelength division device, which are outgoing signal beam and residual pump beam respectively, the separated residual pump light is adjusted in size by a beam expanding system, and then recombined with the outgoing signal beam, and focused on the glass to be processed, the micro-cracks in the glass are formed by the outgoing signal beam, the micro-cracks in the glass are controlled to expand by the modulated residual pump beam, the focused laser spot is scanned along the cutting path of the glass to be processed, and the glass is cut.

2. The glass cutting method according to claim 1, characterized by: The first wavelength is 1020nm-1080nm, and the second wavelength is 910nm-980nm.

3. The method of glass cutting according to claim 1, wherein: The initial signal light is provided by a seed laser source, which is a nanosecond or picosecond pulse laser generator.

4. The method of glass cutting according to claim 3, wherein: The seed laser source is a pulse directly generated by an electrically modulated semiconductor, or a femtosecond mode-locked laser pulse with a wide spectrum of hundreds of picoseconds of pulse width by means of a dispersion element.

5. The glass cutting method according to claim 3, wherein: The output average power of the seed laser source is less than 2W.

6. The method of glass cutting according to claim 1, wherein: The output laser beam is focused on the glass to be processed by a galvanometer and a field lens to cut and fragment the glass.

7. The method of glass cutting according to claim 1, wherein: The output laser beam is focused on the glass to be processed by a converging lens to cut and fragment the glass.

8. The method of glass cutting according to claim 1, wherein: The glass to be processed is arranged on a workbench, and the workbench has the freedom of horizontal two-dimensional movement.

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